A black sedan rolled along Lancaster Avenue past rows of protesters and turned slowly, almost unnoticeably, into the parking lot in front of the Barnes & Noble bookstore in Bryn Mawr. But not completely - political activist Lani Frank glimpsed the vehicle, and then paused from her shouts out front to reflect on what may be the most closely watched election battle of the coming year: The 2006 re-election race of the car's occupant, Pennsylvania Republican Sen. Rick Santorum.

Frank and nearly 100 like-minded voters staked out positions last week to decry statements in Santorum's new book, part of which blames feminism for the destruction of the nuclear family. Others turned out to take issue with the senator's stance on privatizing Social Security. But the real reason that Frank, a member of Temple Brith Achim in King of Prussia, showed up was to push for Santorum's ouster come next November.

"Clearly, the reason is that our current junior senator is out of touch with reality on so many issues," said the mother and volunteer for the Chester County Democratic Coalition, sporting a "Kick Rick Out in 2006" T-shirt, as Santorum took his spot inside at a signing in honor of the release of his first book, It Takes a Family. "At this moment for me, it's anybody but Rick."

Just how such voter anger can effectively coalesce into a Democratic victory at the ballot box remains to be seen, although political observers caution that similar "anybody but Bush" campaigns failed in 2004. The months ahead are sure to find state Treasurer Bob Casey, the frontrunner among three Democrats vying for the nomination who has thus far remained relatively quiet, taking vocal positions on issues from the war in Iraq to health-care reform.

(Philadelphia pension attorney Larry Sandals and college professor Chuck Pennacchio are two lesser-known Democrats facing Casey in the primary.)

But when looking at the 2006 Senate race, some analysts note that Santorum's book release earlier this summer has tended to divide a populace already polarized by the 2004 presidential election. Anecdotal evidence suggests that a majority of voters may already be prepared to give Santorum the boot.

With more than a year to go until Election Day, the pro-life Santorum trails Casey, who's also against abortion, in head-to-head matchups. In the most recent Keystone Poll, for instance, Casey received the backing of 44 percent of respondents, while Santorum garnered 37 percent. Some 19 percent expressed no preference.

"I don't know if [Santorum] garners new support because of the book," said Philadelphia political analyst Jeff Jubelirer. "And I think that's potentially problematic."

Citizen anger was palpable on the early-August night. At the second-floor signing, a demonstrator yelled "Fascist!" while Santorum shook hands with the crowd and signed copies of his book.

Outside along the street, protesters, some dressed as 1950s-era housewives and carrying rolling pins, hoisted signs labeling Santorum a sexist. One man displayed a placard urging the senator, the third-ranking Republican in the U.S. Senate, to go to Iraq in place of American troops.

But Santorum, who was first elected to Congress as a GOP representative from a majority Democratic district near Pittsburgh in 1990, argued at an event earlier that day that his re-election prospects remain strong.

At a gathering in a Lower Merion home billed by organizer Robert Guzzardi, a board member of the Jewish Publishing Group, as a chance for Orthodox and traditional Jews to get to know the senator, Santorum talked up his work on tightening sanctions toward Syria, on producing political change in Iran and on U.N. reform. By the end of the meet-and-greet, he had some from the 40-strong audience not only expressing confidence about 2006, but assuredly speaking about a "President Santorum" in 2008.

Speaking about his book, he then chastised his critics and the media for taking certain statements - comparing abortion to slavery, and castigating two-income families as being "selfish" - out of context.

"I was really impressed that out of a 440-page book, they could only find four sentences that were controversial," said Santorum, laughing at a joke he would repeat later that evening.

In an interview afterward, Santorum pointed to the Lower Merion talk as evidence of his commitment to the Philadelphia suburbs, a swath of southeastern Pennsylvania he needs to win. A large part of that effort, he said, was to reach out to the Orthodox community, a sizable minority in the area.

"I don't think there's any question that the Orthodox community has been outwardly supportive of me," said Santorum. "It's a combination of things. The Orthodox community is very passionate about Israel and about religious freedom."

After the talk, audience member Naphtali Perlberger said that he supported Santorum because of the senator's pro-Israel positions.

"I'm much more focused on his international policies," said Perlberger. "The domestic front is not that important to me."

According to Casey campaign manger Jeff Reiff, though, it's exactly in the domestic arena that the Democrat's camp plans to make gains. On two issues - health care and Social Security - Reiff said that Santorum just comes up short.

"Santorum has done virtually nothing regarding the cost of health care and the access to it," said Reiff. "And on Social Security, in a very populous state for seniors, he has been the cheerleader for the president's privatization plan."

Jubelirer said such statements are a must to produce a Casey win. For the moment, the analyst is predicting a tight race.

"What is telling is you're not seeing in this anger a positive outpouring of support for Casey. You're not seeing Bob Casey stands for X, Y and Z, and we are for X, Y and Z," he said. "His numbers may not move too much, so I think the [polls] will tighten up."